Due to constant inflation and other economic factors it is becoming increasingly desirable for the furniture industry to provide consumers with furniture that is durable, versatile, and, very importantly, of reasonable cost. Today's consumer is concerned not only with styling and structural composition in the furniture he purchases, but equally with getting a good return on each dollar invested. Further, one of the goals in the marketing of collapsible furniture is for the product to be shipped in kit form and set up or assembled by the end consumer, thereby saving on the labor cost. Many consumers also desire units that may be economically shipped from place to place or stored as required in today's mobile society.
To this end, manufacturers have turned to furniture styling, particularly for cabinets, bookcases, chests, etc. which may be collapsed or "knocked-down" for shipping or storage. This collapsible or K-D design has necessitated the associated development of a variety of brackets, hinges and other means for erecting and securing the individual components together.
With particular reference to hinge devices pertinent to the present invention, the prior art includes, among others, U.S. Pat. No. 3,797,905 to Naske, which teaches the use of a flexible sheet material adhesively secured in hinge relation to the inner surfaces of the rear wall and respective side walls of an enclosure. This method does not yield a strong supporting joint and, in fact, a primary objective of the Naske patent is the provision of a dustproof seal in the joint between the connecting walls.
Another device known previously utilizes a flexible sheet material hinge around the outer surface of the rear corner joints and teaches the additional structural support of an interlocking joint.
U.S. Pat. No. 3,933,401 to Lampe et al discloses a prefabricated drawer which includes a molded one-piece polyvinylchloride slab having two v-shaped grooves cut across the width of the slab at the desired rear corner locations to define the back and side walls. When the drawer is to be erected the slanted edges of the v-shaped grooves are coated with adhesive, the points of the grooves are heated to facilitate bending, and the slab is then bent into position to define a back wall and two adjacent said walls. The adhesive coated groove edges permanently seal edge to edge to define the rear corners of the drawer. Another somewhat similar patent is U.S. Pat. No. 3,437,392 to Hilfinger.
Significant problems with the above prior art include: 1) initial lack of compactness when collapsed for shipping; 2) weakness of the hinge joint causing shakey unstable units; and 3) inability, after initial erection, to dismantle the unit for storage or moving.